tests/tcg: expand insn test case to exercise register API

This ensure we at least read every register the plugin API reports at
least once during the check-tcg checks.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240227144335.1196131-25-alex.bennee@linaro.org>

tests/plugin/insn.c

@@ -46,6 +46,25 @@ typedef struct {
     char *disas;
 } Instruction;
 
+/*
+ * Initialise a new vcpu with reading the register list
+ */
+static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index)
+{
+    g_autoptr(GArray) reg_list = qemu_plugin_get_registers();
+    g_autoptr(GByteArray) reg_value = g_byte_array_new();
+
+    if (reg_list) {
+        for (int i = 0; i < reg_list->len; i++) {
+            qemu_plugin_reg_descriptor *rd = &g_array_index(
+                reg_list, qemu_plugin_reg_descriptor, i);
+            int count = qemu_plugin_read_register(rd->handle, reg_value);
+            g_assert(count > 0);
+        }
+    }
+}
+
+
 static void vcpu_insn_exec_before(unsigned int cpu_index, void *udata)
 {
     unsigned int i = cpu_index % MAX_CPUS;
@@ -212,6 +231,8 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
         sizes = g_array_new(true, true, sizeof(unsigned long));
     }
 
+    /* Register init, translation block and exit callbacks */
+    qemu_plugin_register_vcpu_init_cb(id, vcpu_init);
     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
     return 0;